η5-Cyclopentadienyl-stabilized metallacyclopentane and -cycloheptane derivatives of chromium have been isolated, and their chemical behavior lends support to a metallacyclic mechanism for the Cr-catalyzed selective trimerization of ethylene to 1-hexene. In the presence of MAO, the amino-substituted cyclopentadienyl−chromium derivatives show a remarkable activity for the catalytic polymerization of ethylene.

No abstract

No abstract

No abstract

A One-Step Synthesis of 1,4-Bis(1-phospholano)butane.-The phospholanes (III) and (V) are prepared from trimethyl phosphite ( I) and organolithium compounds in a one-pot procedure. -(EMRICH, R.; JOLLY, P. W.; Synthesis (1993) 1, 39-40; Max-Planck-Inst. Kohlenforsch., 45470 Muelheim/Ruhr, Germany; EN)